Use socket in JAVA to implement HTTP requests

Java-based web server implementation mainly uses these two important classes: java.net. Socket and java.net. ServerSocket, and communicates through HTTP messages. An HTTP request consists of three parts: 1. method-Uniform Resource Identifier (URI)-Protocol/version 2. request Header 3. body content [plain] GET/HTTP/1.1 Host: 127.0.0.1: 8080 Connection: keep-alive Accept: text/html, application/xhtml + xml, application/xml; q = 0.9, image/webp, */*; q = 0.8 User-Agent: Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) chrome/30.0.1599.101 Safari/537.36 Accept-Encoding: gzip, deflate, sdch Accept-Language: zh-CN, zh; q = 0.8 HTTP A response is similar to an HTTP request. An HTTP response consists of three parts: 1. method-Uniform Resource Identifier (URI)-Protocol/version 2. response Header 3. the following is an example of an HTTP Response: [plain] view plaincopyprint? HTTP/1.1 200 OK Server: IBM/4.0 Date: Sat, 6 Nov 2013 13:13:00 GMT Content-Type: text/html Last-Modified: Sat, 5 Jan 2013 13:13:12 GMT Content-Length: 112 socket-type socket is an endpoint of the network connection. A socket enables an application to read and write data from the network. Two applications deployed on two different computers can send and receive byte streams through connections. To send a message from your application to another application, you need to instruct the IP address and socket port of another application. The ServerSocket class represents a client Socket, that is, the Socket you construct whenever you want to connect to a remote server application. If a server program depends on the Socket class, it will not work. Your server must be on standby, because it is unknown when the client misses you to send a request. Server Socket is different from Socket. The role of server Socket is to wait for connection requests from the client. Once the server Socket receives a connection request, it creates a Socket instance to communicate with the client. The following is a simple HTTP request implementation: first create an HTTPSERVER service [java] public class HttpServer {public static final String WEB_ROOT = "d:/webroot "; private static final String SHUTDOWN_COMMAND = "/SHUTDOWN"; private boolean shutdown = false; public static void main (String [] args) {HttpServer server = new HttpServer (); server. await ();} public void await () {ServerSocket serverSocket = null; int port = 8080; try {serverSock Et = new ServerSocket (port, 1, InetAddress. getByName ("127.0.0.1");} catch (UnknownHostException e) {e. printStackTrace ();} catch (IOException e) {e. printStackTrace (); System. exit (1);} // Loop waiting for a request while (! Shutdown) {Socket socket = null; InputStream input = null; OutputStream output = null; try {socket = serverSocket. accept (); input = socket. getInputStream (); output = socket. getOutputStream (); // create Request object and parse Request request = new Request (input); request. parse (); // create Response object Response response = new Response (output); response. setRequest (request); response. sendStatic Resource (); // Close the socket; socket. close (); // check if the revious URI is a shutdown command shutdown = request. getUri (). equals (SHUTDOWN_COMMAND);} catch (IOException e) {e. printStackTrace (); continue ;}}} the corresponding service must Request [java] public class Request {private InputStream input; private String uri; public Request (InputStream input) {this. input = input;} public void parse () {// Read a set Characters from the socket StringBuffer request = new StringBuffer (2018); int I; byte [] buffer = new byte [2048]; try {I = input. read (buffer);} catch (IOException e) {e. printStackTrace (); I =-1 ;}for (int j = 0; j <I; j ++) {request. append (char) buffer [j]);} System. out. println ("----------------- request ----------------"); System. out. print (request. toString (); uri = parseUri (request. toString ();} Private String parseUri (String requestString) {int index1, index2; index1 = requestString. indexOf (''); if (index1! =-1) {index2 = requestString. indexOf ('', index1 + 1); return requestString. substring (index1 + 1, index2);} return null;} public String getUri () {return uri ;}} the corresponding Request must have a Response [java] public class Response {private static final int BUFFER_SIZE = 1024; private request Request; private OutputStream output; public Response (OutputStream output) {this. output = output;} public void setRequest (Request re Quest) {this. request = request;} public void sendStaticResource () throws IOException {byte [] bytes = new byte [BUFFER_SIZE]; FileInputStream FD = null; boolean errorFlag = true; if (request. getUri ()! = Null) {File file = new File (HttpServer. WEB_ROOT, request. getUri (); if (file. exists () {fiis = new FileInputStream (file); int ch = fiis. read (bytes, 0, BUFFER_SIZE); while (ch! =-1) {output. write (bytes, 0, ch); ch = FCM. read (bytes, 0, BUFFER_SIZE);} errorFlag = false;} if (errorFlag) {// file not found String errorMessage = "HTTP/1.1 404 File NOT Fount \ r \ n" + "Content-Type: text/html \ r \ n "+" Content-Length: 23 \ r \ n "+" \ r \ n "+"